Echogenic nerve block apparatus and system

ABSTRACT

An apparatus for performing a nerve block procedure, the apparatus being composed of an echogenic needle or an echogenic soft tissue tunneling device and an echogenic catheter configured for controlled delivery of a medication. The apparatus may further include a sheath such that at least one of the needle or tunneling device and sheath is echogenic. The present invention also encompasses a system for performing a nerve block procedure, the system includes introducing an echogenic needle in the general area of a nerve bundle, positioning the echogenic needle adjacent the nerve bundle utilizing sonic imaging techniques, introducing an echogenic catheter configured for controlled delivery of a fluid through the echogenic needle, withdrawing the echogenic needle, positioning the echogenic catheter adjacent the nerve bundle utilizing sonic imaging techniques, and delivering fluid to the nerve bundle through the echogenic catheter.

This application claims the benefit of priority from U.S. ProvisionalApplication No. 61/394,040 filed on Oct. 18, 2010, the contents of whichare incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to pain management systems, and more specificallyto catheter-based infusion systems for the administration of fluids.Most specifically, this invention relates to an apparatus and system forperforming a nerve block procedure.

BACKGROUND OF THE INVENTION

Prior to performing a surgical operation on a part of the body, such asfor example the arms or legs, it may be desirable to perform a nerveblock in order to anesthetize a nerve bundle in a part of the bodyproximate to where surgery will occur. Often, a catheter-based infusionsystem is utilized to both block the nerve bundle for surgery and toprovide a continuous, low flow rate of the anesthetic over a period oftime (e.g., 2-3 days following surgery) for post-operative painmanagement.

One approach is to introduce an epidural-type needle or needle andpeel-away-type sheath into the general area of the desired nerve bundle.Once proper location of the needle is achieved, a test dose of theanesthetic may be provided through the epidural needle and a cathetermay be introduced through the needle to administer the anesthetic andmaintain the nerve block.

Several methods of targeting needle location exist today—insulatedneedles having an integral conductive wire such that a small amount ofcurrent may be pulsed through the needle or catheter by a nervestimulator (i.e., a current generator). An electrical current of 0.1 toabout 2 mA will induce motor movement in the patient when the tip of theneedle (frequently called a “stimulating needle”) is near the nerve.When the stimulating needle is probed into the general area of thedesired nerve bundle, the pulsing current stimulates the nerve andcauses a motor response to assist in properly locating the needle. Asthe current is reduced, the motor effect is also reduced so a needlethat causes movement at a low current is likely to be very close to thedesired area for drug delivery.

One problem with this approach is that the catheter insertion throughthe needle may move the tip of the needle away from the target zone.Alternatively and/or additionally, the tip of the catheter may curl awayfrom the target zone during insertion.

Several manufacturers have designed stimulating catheters that correctthis problem by passing the current first through the needle and thenseparately through the catheter. The problem with this is that thecatheter cannot be steered to the target zone without risking pullingback through the needle and potentially damaging the catheter. Inaddition, the additional time needle to place and maneuver the catheteris significant and after the catheter is secured, it can dislodge bypatient movement and then become ineffective.

Ultrasound guided techniques have added imaging to the procedure, butthey are mainly used to see the adjacent vessels and are not always goodat seeing the needle and/or catheter. The problem with ultrasound guidedtechniques is that the needle and catheter cannot be easily seen throughtissue. That is, the ability to see the tip and/or other portions of theneedle and/or catheter under ultrasound imaging techniques is limited.Another problem is that conventional catheters do not allow one to placethe catheter quickly allowing for some small migration or tipmis-positioning while still delivering drug to the target area.

A variety of approaches have been used to enhance ultrasonic imaging ofmedical devices by increasing the acoustic reflection coefficient of thedevices. In U.S. Pat. No. 4,401,124 issued to Guess et al., thereflection coefficient of a biopsy needle is enhanced by the use of adiffraction grating disposed on the surface of the needle. A variety ofmechanisms for enhancing the ultrasound image of a portion of a medicalinstrument are also disclosed in U.S. Pat. No. 5,289,831 issued toBosley, U.S. Pat. No. 5,201,314 issued to Bosley et al. and U.S. Pat.No. 5,081,997, also issued to Bosley et al. These patents disclosecatheters and other devices provided with echogenic surfaces includingspherical indentations or projections in the range of 0.5 to 100 micronsor fabricated of material incorporating glass spheres or high densitymetal particles in the range of 0.5 to 100 microns. The use ofmicro-bubbles introduced into polymers to provide echogenic cathetercomponents is described in U.S. Pat. No. 5,327,891, issued to Rammler.

However, these features add complexity to manufacturing and maynegatively impact the performance of a catheter having a plurality ofexit holes along a portion of the catheter. For example, glass beadsadhered to the exterior of a catheter may become dislodged. Glass beadsincorporated into the polymer matrix may create difficulties duringcreation of exit holes. Microbubbles formed in the polymer matrix of thecatheter wall can be difficult to form reliably during the extrusionprocess. Spherical indentations or spherical protuberances can bechallenging and/or expensive to form on a single use item. For example,an EchoTip® Ultrasound Needle has a plurality of spherical indentationsthat can increase acoustic reflection. However, these sphericalindentations can be difficult or expensive to produce in a metal needleand may be ineffective when implemented in items that are generally notvery acoustically reflective such as, for example, a polymer catheter.

SUMMARY OF THE INVENTION

The present invention addresses these problems by providing an apparatusfor performing a nerve block procedure, the apparatus being composed ofan echogenic needle and an echogenic catheter configured for controlleddelivery of a medication.

The present invention also encompasses a system for performing a nerveblock procedure, the system includes introducing an echogenic needle inthe general area of a nerve bundle, positioning the echogenic needleadjacent the nerve bundle utilizing sonic imaging techniques,introducing an echogenic catheter configured for controlled delivery ofa fluid through the echogenic needle, withdrawing the echogenic needle,positioning the echogenic catheter adjacent the nerve bundle utilizingsonic imaging techniques, and delivering fluid to the nerve bundlethrough the echogenic catheter.

An aspect of the present invention encompasses addresses an echogenicneedle configured for placement into the body adjacent a nerve bundle.The echogenic needle has a distal end composed of an echogenic needletip, a hollow needle body, and a proximal end that includes a fitting.The needle body may be an echogenic needle body.

Generally speaking, the echogenic needle tip may be formed from cobaltchromium (also referred to as “cobalt chrome”), glass or other materialhaving a high degree of acoustic impedance. Alternatively and/oradditionally, the echogenic needle tip may have a shape or spatialconfiguration that reflects an effective amount of acoustic waves so thetip is satisfactorily visible during sonic imaging. Suitable shapes forthe echogenic needle tip include beveled, generally planar surfaces.Alternatively and/or additionally, grooves and/or indentations may beadded to the needle.

The needle tip and/or the needle body may be rendered echogenic bycoating the needle tip and/or a surface of the needle body with amaterial that increases acoustic impedance. Exemplary materials includetitanium carbide, titanium nitride, titanium aluminum nitride, titaniumaluminum carbon nitride and similar materials. Hard, dense, amorphousnon-crystalline solids such as glass, acrylic glass—also referred to aspoly(methyl methacrylate), and hard, glassy hydrogels such as thosedescribed in US Patent Application Publication No. US 2006/0141186 mayalso be used. The needle tip and/or needle body may be renderedechogenic by coating the needle tip and/or a surface of the needle bodywith various known echogenic coatings.

Another aspect of the present invention encompasses an echogeniccatheter configured for controlled delivery of a fluid across ananatomical region. The echogenic catheter is composed of an elongatedtubular member and an echogenic catheter tip. The elongated tubularmember may be an elongated tube with a plurality of exit holes or slotsin a portion of the elongated tube, and an elongated porous memberresiding within the tube. Alternatively, the elongated tubular membermay be made of a porous membrane such as a filtration membrane.Exemplary filtration membranes may be made of polytetrafluoroethylene.

The echogenic catheter tip may be a portion of a distal end of thecatheter formed from cobalt chrome, glass, or other material having ahigh degree of acoustic impedance. Alternatively and/or additionally,the echogenic catheter tip may be or may include an echogenic insert orplug formed from or coated with cobalt chrome, glass, or other materialhaving a high degree of acoustic impedance. The echogenic catheter tip,insert or plug may have a shape or spatial configuration that reflectsan effective amount of acoustic waves so the tip is satisfactorilyvisible during sonic imaging. Suitable shapes include gear shapes (e.g.,circular or cylindrical shapes having grooves, notches and/orcrenulations that provide a plurality of flat reflective surfaces),spherical shapes, multi-faceted geometric shapes formed by interlockingpolygons (e.g., a geodesic dome shape). Sharp and/or flat edges of theechogenic insert may engage the walls of the lumen defined by thecatheter body to prevent the echogenic insert from moving relative tothe elongated tubular member.

The elongated tubular member of the catheter (and/or the catheter tip)may be rendered echogenic by coating an internal or external surfacewith a material that increases its acoustic impedance. Exemplarymaterials include titanium carbide, titanium nitride, titanium aluminumnitride, titanium aluminum carbon nitride and similar materials. Hard,dense, amorphous non-crystalline solids such as glass, acrylicglass—also referred to as poly(methyl methacrylate, and hard, glassyhydrogels such as those described in US Patent Application PublicationNo. US 2006/0141186 may also be used. The elongated tubular member(and/or the catheter tip) may be rendered echogenic by coating it withvarious known echogenic coatings.

The coating may be on the outside of the elongated tubular member or thecoating may be located on the interior of the elongated tubular member.In some aspects of the invention, the coating on the interior of theelongated tubular member may be a coating that incorporates acousticallyreflective particles in a carrier. For example, the coating may includespherical beads of glass or other acoustically reflective material in acarrier that binds spherical beads to an internal surface of theelongated tubular member.

According to another aspect of the invention, the elongated tubularmember of the catheter may be rendered echogenic by including aninternal component that increases its acoustic impedance. The internalcomponent may be an elongated tubular coil spring enclosed within thetubular member. The elongated tubular coil spring may be may formed froman echogenic material, may be coated with a material that increases itsacoustic impedance, or may have a surface that is modified with grooves,diffraction gratings, flattened portions, dimples or the like toincrease its acoustic impedance. Alternatively and/or additionally, theinternal component may be a component that actively generates acousticwaves that are visible during sonic imaging. Such a component mayinclude an energy source and a transducer such as, for example apiezoelectric transducer that converts the energy into acoustic waves.

In embodiments where the elongated tubular member is an elongated tubewith a plurality of exit holes or slots in a portion of the elongatedtube and an elongated porous member resides within the tube, it iscontemplated that the elongated porous member may be made of or mayinclude material that increases its acoustic impedance.

Other objects, advantages and applications of the present disclosurewill be made clear by the following detailed description of a preferredembodiment of the disclosure and the accompanying drawings whereinreference numerals refer to like or equivalent structures.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an exemplary echogenic needle.

FIGS. 2A to 2D are illustrations of illustrated exemplary shapes forincreasing the acoustic impedance of a needle tip.

FIG. 3 is an illustration of cross-section of the exemplary echogenicneedle of FIG. 1 taken across line A-A.

FIG. 4 is an illustration of an exemplary echogenic catheter.

FIG. 5 is an illustration of cross-section of the exemplary echogeniccatheter of FIG. 4 taken across line B-B.

FIG. 6 is an illustration of a detail of an exemplary echogenic cathetershowing an exemplary echogenic catheter tip.

FIG. 7 is an illustration of a detail of an exemplary echogenic catheterincluding an exemplary echogenic catheter tip.

FIG. 8 is an illustration of a detail of an exemplary echogenic cathetershowing an exemplary echogenic insert or plug.

FIG. 9 is an illustration of a cross-section of the exemplary echogeniccatheter of FIG. 8 taken across line C-C.

FIG. 10 is an illustration of an exemplary echogenic catheter tip.

FIG. 11 is an illustration of a cross-section of an exemplary echogeniccatheter showing an exemplary echogenic insert or plug.

FIG. 12A is an illustration of an exemplary echogenic catheter tip.

FIG. 12B is an illustration of an exemplary echogenic catheter tip.

FIG. 12C is an illustration of an exemplary echogenic catheter tip.

FIG. 13A is an illustration of an exemplary echogenic catheter showingan exemplary echogenic insert or plug.

FIG. 13B is an illustration of a cross-section of the exemplaryechogenic catheter of FIG. 13A taken across line D-D.

FIG. 14A is an illustration of an exemplary echogenic catheterincorporating an exemplary echogenic bead.

FIG. 14B is an illustration showing a detail of an exemplary echogenicbead from FIG. 14A.

FIG. 15A is an illustration of an exemplary echogenic catheterincorporating voids or bubbles in the catheter.

FIG. 15B is an illustration showing a detail of the echogenic catheterfrom FIG. 15A.

FIG. 16A is an illustration of an exemplary echogenic catheterincorporating a catheter having an elongated shaft.

FIG. 16B is an illustration showing a detail of the echogenic catheterfrom FIG. 16A.

FIGS. 17A to 17C are illustrations of an exemplary echogenic catheterincorporating a spring.

FIG. 18 is an illustration of an exemplary echogenic catheterincorporating a guide wire.

FIG. 19 is an illustration of an exemplary echogenic catheterincorporating a metal band.

FIG. 20 is an illustration showing a cross-section of the catheterincorporating a metal band from FIG. 19.

DETAILED DESCRIPTION

FIGS. 1-3 illustrate aspects of an exemplary echogenic needle configuredfor placement into the body adjacent a nerve bundle. Referring to FIG. 1the echogenic needle 10 has a distal end 12 composed of an echogenicneedle tip 14 that may terminate in a beveled aperture having includebeveled, generally planar surfaces to enhance acoustic impedance.Examples of needles having such surfaces include, but are not limitedto, PAJUNK needles or QUINCKE needles. The echogenic needle 10 furtherhas a hollow needle body 16, and a proximal end 18 that may include aconventional fitting 20.

For example, the echogenic needle may generally have the configurationof a conventional TUOHY needle except for the echogenic featuresdescribed herein. A suitable needle may be an 18 gauge, steel TUOHYneedle with a HUBER tip and a TUOHY hub. Such TUOHY needles arecommercially available, with a non-insulated tip and a plastic hub asrespective integral portions of the needle. Such TUOHY needles areavailable in various lengths. The needle may also be a WEISS epiduralneedle having fixed wings.

Generally speaking, the echogenic needle tip may be formed from orcoated with cobalt chromium (also referred to as “cobalt chrome”), glassor other material having a high degree of acoustic impedance.Alternatively and/or additionally, the echogenic needle tip may have ashape or spatial configuration that reflects an effective amount ofacoustic waves so the tip is satisfactorily visible during sonicimaging.

Referring now to FIGS. 2A, 2B and 2C, there are illustrated exemplaryshapes for increasing the acoustic impedance of a needle tip. FIG. 2A isa side view of an exemplary needle 22 in which a needle body or shaft 24terminates in a generally flat, planar surface 26. An additional planarsurface 28 can be seen at the very tip of the needle. FIG. 2B is anillustration showing a top view of the needle shown in FIG. 2A. In thisillustration, needle body or shaft 24 terminates in a generally flat,planar surface 26 which provides surface area to enhance reflection ofsonic energy. Additional planar surfaces 28 can be seen at the very tipof the needle. The needle illustrated in FIGS. 2A and 2B is sometimesreferred to as a QUINCKE needle or a needle having a QUINCKE-type point.FIG. 2C is an illustration of an exemplary needle 22 in which a needlebody or shaft 24 terminates in a generally flat, planar surface 26 whichprovides surface area to enhance reflection of sonic energy. The needleillustrated in FIG. 2C is sometimes referred to as a PAJUNK needle or aneedle having a PAJUNK-type point.

A useful embodiment of a needle is a WEISS epidural needle. Inparticular, the needle may be a WEISS epidural needle supplied by BectonDickinson (BD) having fixed wings and a modified TUOHY point. The needlemay be a five-inch, 18 gauge needle and is identified by the BD productnumber 405190. It should be appreciated, however, that other types ofsuitable epidural needles may also be utilized.

The needle tip and/or the needle body may be rendered echogenic bycoating the needle tip and/or a surface of the needle body with amaterial that increases acoustic impedance. FIG. 3 illustrates across-section of the hollow needle body 16 taken along line A-A inFIG. 1. As can be seen in FIG. 3, a coating 32 is applied over theneedle body 34. Generally speaking, the coating can be applied over onlythe needle tip and/or over portions of the needle body (e.g., bands).The coating may be applied by mask and dip techniques. The coatingthickness may vary depending on the coating material and itseffectiveness at increasing acoustic impedance. For example, the coatingmay be 1 micrometer in thickness.

Exemplary materials that may be used to coat the needle body 16 includetitanium carbide, titanium nitride, titanium aluminum nitride, titaniumaluminum carbon nitride, or similar materials may be used. Hard, dense,amorphous non-crystalline solids such as glass, acrylic glass—alsoreferred to as poly(methyl methacrylate), and hard, glassy hydrogelssuch as those described in US Patent Application Publication No. US2006/0141186 published Jun. 29, 2006 by Janssen et al. for “Gloves WithHydrogel Coating For Damp Hand Donning and Method of Making Same” mayalso be used. The needle tip and/or needle body may be renderedechogenic by coating the needle tip and/or a surface of the needle bodywith various known echogenic coatings such as described in U.S. Pat. No.6,506,156 issued Jan. 14, 2003 to Jones et al. for “Echogenic Coating”;U.S. Pat. No. 7,229,413, issued Jun. 12, 2007 to Violante et al. for“Echogenic Coatings With Overcoat”; and in U.S. Patent ApplicationPublication No. US 2009/0318746 A1, published Dec. 24, 2009 to Thurmond,II et al. for “Lubricious Echogenic Coatings”, the contents of which areincorporated by reference.

Referring now to FIG. 2D, there is illustrated in perspective view adetail of an exemplary needle 22 that is rendered echogenic by joiningor incorporating echogenic elements 29 at or near the very tip of theneedle. The needle 22 has a needle body or shaft 24 that terminates in agenerally flat, planar surface 26. In this particular example, theneedle has a slight curve or bends 27 near the tip of the needle thatdefines the flat planar surface 26. The echogenic elements 29 may beglass beads, spherical particles, grooves, indentations or otherfeatures that do not interfere with the function of the needle. Theneedle illustrated in FIG. 2D is sometimes referred to as a TUOHY needleor a needle having a TUOHY-type point.

FIGS. 4-11 illustrate aspects of an exemplary echogenic catheter. Whilethe catheter may desirably be configured for controlled delivery of afluid across an anatomical region, the catheter may be configured forother purposes. Generally speaking, the design of the catheter may besimilar to conventional catheters except that the catheters are modifiedto include or incorporate echogenic elements. Exemplary cathetersinclude those described in U.S. Pat. No. 6,350,253 issued Feb. 26, 2002to Deniega et al. for “Catheter For Uniform Delivery of Medication”, thecontents of which are incorporated herein by reference.

Referring now to FIG. 4, the echogenic catheter 100 is composed of anelongated tubular member 102 having a proximal end 104, a distal end 106and an echogenic catheter tip 108 at its distal end 108. The elongatedtubular member 102 may be an elongated tubular member 102 with aplurality of exit holes 112 in one or more portions 114 of the elongatedtubular member. FIG. 5 illustrates a cross-section of the elongatedtubular member 102 taken along line B-B in FIG. 4 illustrating a porousmember 116 residing within the tubular member 102. An annular space 118may be present between the porous member 116 and the elongated tubularmember 102. Alternatively, the elongated tubular member 102 may be madeof a porous membrane.

The echogenic catheter tip 108 may be a portion of a distal end 106 ofthe catheter 100 and may be formed from cobalt chrome, glass, quartz,crystalline mineral, or other material having a high degree of acousticimpedance. Another exemplary material may be stainless steel. As shownin FIG. 6, the echogenic catheter tip 108 may include a support 120. Theechogenic catheter tip 108 may be formed integrally with the support 120or may be adhesively bonded thereto. The support 120 may optionally beechogenic. Generally speaking, the echogenic catheter tip 108 may becircular and has a diameter such it is aligned with the outer edges ofthe ribs 122 of the support 120, as shown.

Referring to FIG. 7, there is shown an embodiment in which the echogeniccatheter tip 108 incorporates reflective flakes 130, reflective spheres132 and/or reflective particles 136 in a carrier matrix 138 of materialsuch as, for example, silicone or other suitable and compatible medicalgrade plastic that can be used for the catheter tip 108. Exemplaryreflective flakes 130 include gold flakes, silver flakes or the like.Reflective spheres 132 include gold spheres, silver spheres, glassspheres or the like. Reflective particles 136 include gold particles,silver particles, glass particles or the like.

Alternatively and/or additionally, the echogenic catheter tip 108 caninclude a very dense material incorporated into the carrier matrix at adistal location to generate a high degree of impedance mismatch. Densematerial could also be incorporated into the tubular member 102 in adistal location to generate a high degree of impedance mismatch.

Appropriate selection of dense materials can create a sufficient levelof difference in the acoustic impedance of the tip 108 and/or portion ofthe elongated tubular member 102 and the acoustic impedance of thesurrounding tissue to create a level of reflection that allowsvisualization of the tip and/or portion of the elongated tubular member102 utilizing sonic imaging techniques.

One category of relatively dense materials is radio-opaque materials.These materials may be added to the polymer used to make the catheter orthe tip. Radio-opaque materials are those that absorb and/or blockx-rays from passing through an item. These include iodine and bariumsubstances, bismuth salts, tungsten, gold metal, halogenated moieties,metal containing, optically transparent polymers and mixtures thereof.

Halogenated moieties like halogenated diols and halogenateddi-isocyanate reactants may be used to prepare polyurethane that isradio-opaque and desirably visually transparent. It has been found thatpreparing polyurethane using trans cyclo-hexane 1,4 diisocyanate(t-CHDI) can produce a toxicologically harmless product that isradio-opaque yet visibly transparent. More information on this processmay be found in European Patent Application EP 0 523 928 A2 publishedJan. 20, 1993 by Wagener et al. for “Kink Resistant, Flexible,Radiopaque Polyurethane Tubing and Catheters Formed Therefrom”, thecontents of which are incorporated by reference.

The radio-opaque additive may be present in an amount between 5 and 60weight percent, more desirably 10 and 40 weight percent or still moredesirably between 20 and 30 percent. The radio-opaque additive may becompounded with the polymeric material from which the tube is made inthe conventional manner; e.g., barium sulfate powder is compounded intothe polymer through extrusion compounding to produce resin pellets atthe proper weight percent addition rate.

It is contemplated that dense materials may be banded or utilized insegments to provide contrast during sonic imaging. For example, a bandor segment may contain little or no radio-opaque additive and anotherband or segment may contain at least 5 to 10 weight percent more thanthe section having little or none of the additive. It is alsocontemplated that both types of bands or segments may contain aradio-opaque material which may be different in type and/or amount,resulting in a different degree of density for the bands or segments(e.g. tungsten in one band or segment and barium sulfate in another bandor segment). This differential in density may allow one to discern thelocations of the bands or segments utilizing sonic imaging because ofdifferences in acoustic impedance.

Alternatively and/or additionally, the echogenic catheter tip may be ormay include an echogenic insert or plug 120 formed from or coated withcobalt chrome, glass, quartz, crystalline mineral, or other materialhaving a high degree of acoustic impedance. Referring now to FIG. 8, theechogenic catheter 100 may incorporate an echogenic insert or plug 150having a shape or configuration that reflects an effective amount ofacoustic waves so the tip or other portion (or portions) of the catheterincorporating such an insert is visible during sonic imaging. That is,the combination of an appropriate shape or configuration with anechogenic material or echogenic coating is thought to greatly enhancethe acoustic reflectivity of the insert or plug. Suitable shapes includegear shapes (e.g., circular or cylindrical shapes having grooves,notches and/or crenulations that provide a plurality of flat reflectivesurfaces), spherical shapes, multi-faceted geometric shapes formed byinterlocking polygons (e.g., a geodesic shape). FIG. 9 illustrates across-section of the elongated tubular member 102 taken along line C-Cin FIG. 8 illustrating an echogenic insert or plug 150 residing withinthe tubular member 102. As can be seen in FIG. 9, the echogenic insertor plug 150 has a “star” shaped cross section defined by spines 152extending radially outward from an axial or core region 154 to define aseries of grooves 156 in the echogenic insert 150.

FIG. 10 illustrates how such a feature may be incorporated in a cathetertip 108 of the type shown in FIG. 6 such that at least a portion of thecatheter tip is echogenic. That is, the catheter tip, the support orboth may be echogenic. The catheter tip 108 includes a support 120 thatmay be formed integrally with the catheter tip or may be adhesivelybonded thereto. The support 120 may be generally the same as theillustrated in FIG. 6 except that it is made of or coated with anacoustically reflective material and configured to have a shape that isacoustically reflective. For example, the support may have geometrysimilar to the echogenic insert illustrated in FIGS. 8 and 9. Referringto FIG. 10, the support 120 has a “star” shaped cross section that maybe described spines 152 extending radially outward from an axial or coreregion 154 to define a series of grooves 156. In other words, thecatheter tip may itself be echogenic and/or it may include a supportthat is echogenic.

FIG. 11 illustrates a cross-section of the elongated tubular member 102taken along line C-C in FIG. 8 illustrating another exemplary echogenicinsert or plug 150 residing within the tubular member 102. As can beseen in FIG. 11, the echogenic insert or plug 150 has a “gear” shaped orcrenulated cross section defined by protuberances 158 extending radiallyoutward from an axial or core region 154 to define a series of notches160.

FIG. 12A illustrates another example of such a feature incorporated in acatheter tip 108 of the type shown in FIG. 6 such that at least aportion of the catheter tip is echogenic. The catheter tip 108 includesa support 120 that may be formed integrally with the catheter tip or maybe adhesively bonded thereto. In this example, the support 120 isgenerally the same as the echogenic insert illustrated in FIG. 11 andhas a “gear” shaped or crenulated cross section defined by protuberances158 extending radially outward from an axial or core region 154 todefine a series of notches 160.

FIG. 12B illustrates another exemplary catheter tip 108 that includes asupport 120 that may be formed integrally with the catheter tip. Thesupport resides within the tubular member 102 and may be secured byadhesive or by a friction fit or by other mechanical fastening means.This catheter tip has an “hourglass” shape and a surface that is free ofcrenulations or other complex geometries. FIG. 12C illustrates anotherexemplary catheter tip 108 that includes a support 120 that may beformed integrally with the catheter tip. The support resides within thetubular member 102 and may be secured by adhesive or by a friction fitor by other mechanical fastening means. This catheter tip has a “bullet”shape and a surface that is free of crenulations or other complexgeometries. These relatively simple shapes are desirably made ofstainless steel but other materials having a high degree of acousticimpedance may be used including, but not limited to cobalt chrome,glass, or quartz.

As generally illustrated in FIGS. 8, 9 and 11, the sharp and/or flatedges of the echogenic insert (or support) may engage the walls of thelumen defined by the elongated tubular member 102 to prevent theechogenic insert (or the echogenic catheter tip) from moving relative tothe elongated tubular member.

Alternatively and with reference to FIG. 13A, the echogenic catheter 100may incorporate an echogenic insert or plug 150 within the elongatedtubular member 102. The echogenic insert or plug 150 may be made ofglass, quartz crystal or similar material and has a generallycylindrical shape or configuration and which includes one or more tubesor cylindrical channels 170 that passes through the material to create adensity difference that is visible using sonic imaging. FIG. 13B is across-sectional view of the echogenic catheter shown in FIG. 13A takenalong line D-D. As illustrated in FIG. 13B, the tubular member 102incorporates an echogenic insert 150 having a cylindrical cross sectionand one or more tubes or cylindrical channels 170 that passes throughthe material to create a density difference that is visible using sonicimaging.

In an aspect of the invention, the echogenic catheter 100 mayincorporate an echogenic bead 172 having a spherical or spheroid shapewithin the elongated tubular member 102 as illustrated in FIG. 14A. Theechogenic bead 172 may be made of glass, quartz crystal or similarmaterial or may be made of any conventional non-echogenic material andprovided with an echogenic coating. The echogenic bead has a pluralityof dimples 174 and may further include rugosities or wrinkles to enhancevisibility using sonic imaging. FIG. 14B is a perspective view showing adetail of the echogenic bead 172 highlighting the dimples andrugosities.

FIG. 15A is a cross-sectional view of an exemplary echogenic catheter100 illustrating voids or bubbles 176 formed in the elongated tubularmember 102. These voids or bubbles are generated during manufacture ofthe catheter. The voids or bubbles may be created by introducing a gasinto the polymer that is extruded to form the catheter. The voids orbubbles may also be created by the extrusion process, by mixing a gasgenerating material with the polymer or by other conventionaltechniques. Desirably, the voids or bubbles 176 are present in thematerial of the elongated tubular member 102 as illustrated in FIG. 15Band are not present at the surface of the elongated tubular member. Itis generally thought that the voids or bubbles in the polymer materialcan provide sufficiently high degree of impedance mismatch to allowvisualization through sonic imaging. It is contemplated that materialsmay be mixed with the polymer to increase the density of the polymer tofurther enhance the degree of impedance mismatch. Exemplary materialsare described above and may include radio-opaque materials.

FIG. 16A is an illustration of an elongated tubular member 102 of anechogenic catheter 100 incorporating at its distal end 106 an echogeniccatheter tip 108 having a shaft 180. The catheter tip 108 may be madeechogenic generally as described above or it may further include bands182 of an echogenic material. It is contemplated that the bands may beglass, quarts or other echogenic material. It is also contemplated thatthe bands may be a material having a high degree of impedance mismatchto allow visualization through sonic imaging. FIG. 16B illustrates adetail of the echogenic catheter tip 108 having a shaft 180 thatincorporates a band or insert 182 of an echogenic material or a materialhaving a high degree of impedance mismatch to allow visualizationthrough sonic imaging.

According to an aspect of the invention, the catheter 100 mayincorporate a metal spring 190 within the elongated tubular member 102.Generally speaking, the metal spring 190 may be used to providekink-resistance. The metal spring 190 may be modified to enhance itsacoustic impedance. The can be accomplished by changing the generallyround cross-section 192 of the metal spring 190 as illustrated in FIG.17B into a generally flat cross-section 194 as illustrated in FIG. 17C.This generally flat cross-section 194 may be provided in portions oralternating regions of the metal spring and/or it may be located at thedistal end 106 of the catheter. It is contemplated that the metal spring190 may be made actively echogenic by being connected to a transducerthat vibrates the spring at a frequency sufficient to generate acousticwaves that are visible through sonic imaging. Such a transducer may be,for example a piezoelectric transducer. Other types of transducers mayinclude magnetostrictive transducers, electromagnetic transducers, orlaser-activated elements may be used.

The catheter 100 may be made echogenic by incorporating a removableechogenic guide wire 200 in the catheter. The guide wire 200 may beechogenic because it is formed it out of an echogenic material orbecause of an applied echogenic coating. Alternatively and/oradditionally, an echogenic guide wire tip 202 may be added to theechogenic guide wire 200. It is contemplated that the guide wire 200 mayinclude a strand or additional wire 204 that is formed it out of anechogenic material, contains an applied echogenic coating such that itis passively echogenic. The strand or additional wire may be configuredto vibrate due to a connection with a transducer.

Catheters frequently are manufactured with one or more metal band orrings. In an aspect of the invention, such metal bands or rings may bemodified so they are echogenic. Referring to FIG. 19, there is shown anillustration of an exemplary catheter 100 having a plurality of exitholes 112 and which incorporates a first metal band 250 near the distalend 106 of the catheter and a second metal band 252. Referring to FIGS.19 and 20, the bands may have a cross section that may be described asdefining spines, protuberances, crenels or the like 254 extendingradially outward from the elongated tubular member 102. It should benoted that the protuberances 254 are recessed in the catheter so they donot protrude beyond outermost radial surface of the elongated tubularmember 102. Alternatively and/or additionally, the metal bands mayinclude grooves, indentations, cross-hatching or the like to enhancevisualization by sonic imaging techniques.

In an aspect of the invention, the metal band or metal bands and/or anyechogenic component(s) of the catheter may be configured to provideinformation about the catheter. Desirably, that information is providedduring sonic imaging and is interpreted based on the intensity orplacement (or combinations thereof) of the echogenic components. Inanother aspect of the invention, one or more chart(s) or other tool(s)may be provided to allow others (e.g., medical professionals) tointerpret the information. Alternatively and/or additionally, the imageprovided during sonic imaging may be interpreted by the sonic imagingequipment. Examples of information about the catheter that may beprovided include, but are not limited to, exit hole placement, exit holedensity, length, diameter (or other size information), whether thecatheter has an open tip, whether the catheter has a closed tip, and thelike.

The elongated tubular member 102 of the catheter 100 may be renderedechogenic by coating an internal or external surface with a materialthat increases its acoustic impedance. Exemplary materials includetitanium carbide, titanium nitride, titanium aluminum nitride, titaniumaluminum carbon nitride or similar materials. Hard, dense, amorphousnon-crystalline solids such as glass, acrylic glass—also referred to aspoly(methyl methacrylate, and hard, glassy hydrogels such as thosedescribed in US Patent Application Publication No. US 2006/0141186published Jun. 29, 2006 by Janssen et al. for “Gloves With HydrogelCoating For Damp Hand Donning and Method of Making Same” may also beused.

The coating may be on the outside of the elongated tubular member or thecoating may be located on the interior of the elongated tubular member.In some aspects of the invention, the coating on the interior of theelongated tubular member may be a coating that incorporates acousticallyreflective particles in a carrier. For example, the coating may includespherical beads of glass or other acoustically reflective material in acarrier that binds spherical beads to an internal surface of theelongated tubular member.

Alternatively and/or additionally, the elongated tubular member (and/orthe catheter tip) may be rendered echogenic with various known echogeniccoatings such as described in U.S. Pat. No. 6,506,156 issued Jan. 14,2003 to Jones et al.; U.S. Pat. No. 7,229,413, issued Jun. 12, 2007 toViolante et al.; and in U.S. Patent Application Publication No. US2009/0318746 A1, published Dec. 24, 2009 to Thurmond, II et al., thecontents of which are incorporated by reference. According to anotheraspect of the invention, the elongated tubular member of the cathetermay be rendered echogenic by including an internal component thatincreases its acoustic impedance. The internal component may be anechogenic metal wire or even an elongated tubular coil spring enclosedwithin the tubular member. The elongated tubular coil spring may be mayformed from an echogenic material, may be coated with a material thatincreases its acoustic impedance, or may have a surface that is modifiedwith grooves, diffraction gratings, dimples or the like to increase itsacoustic impedance.

Alternatively and/or additionally, the internal component may be acomponent that actively generates acoustic waves visible during sonicimaging. Such a component may include an energy source or may beconnected to an energy source and may further include a transducer suchas, for example a piezoelectric transducer that converts the energy intoacoustic waves. Other types of transducers including magnetostrictivetransducers, electromagnetic transducers, or laser-activated elementsmay be used.

In embodiments where the elongated tubular member is an elongated tubewith a plurality of exit holes or slots in a portion of the elongatedtube and an elongated porous member resides within the tube, it iscontemplated that the elongated porous member may be made of or mayinclude material that increases its acoustic impedance. Examples includeporous composites that may include spherical beads of glass or otheracoustically reflective material, batts or webs formed of thermoplasticpolymer fibers having entrapped along the length thereof bubbles of agas, a porous matrix composed of a polymer network having gas filledclosed cells distributed in the matrix, or similar structures. Anexample of a batt or web formed of thermoplastic polymer fibers havingentrapped along the length thereof bubbles of a gas can be founding U.S.Pat. No. 6,395,215 issued May 28, 2002 to Jameson for “Method andApparatus for Ultrasonically Assisted Melt Extrusion of Fibers”, thecontents of which is incorporated herein by reference. An example of aporous matrix composed of a polymer network having gas filled closedcells distributed in the matrix, or similar structures can be found inU.S. Pat. No. 7,160,553 issued Jan. 9, 2007 to Gibbins et al. for“Matrix for Oxygen Deliver to Compromised Tissues”, the contents ofwhich is incorporated herein by reference.

The present invention encompasses an apparatus for performing a nerveblock procedure. The apparatus is composed of an echogenic needle asdescribed above and an echogenic catheter configured for controlleddelivery of a medication as described above. The apparatus may furtherinclude an echogenic sheath. Exemplary echogenic sheaths are describedin U.S. Patent Application Publication No. US 2009/0005774 A1, publishedJan. 1, 2009 to Fernald, the contents of which are incorporated byreference. Such an echogenic sheath may be rendered echogenic by any ofthe above described materials or techniques or combinations thereof. Itmay, however, be desirable to also render the sheath echogenic to aid inthe guidance procedure and to ultrasonically verify placement of thesheath after removal of the needle. In this regard, the sheath maycontain any manner echogenic material, such as metal threads or flakes,formed with the sheath or subsequently added to the surface of thesheath. In another embodiment, the sheath may be rendered effectivelyechogenic by simply defining holes or perforations through the sheathsuch that that the metal needle is exposed through the perforationsduring the ultrasonically imaging. By detecting axial points or sectionsof the needle through the sheath, the location of the sheath is alsoverified.

The present invention also encompasses a system for performing a nerveblock procedure. The system includes introducing an echogenic needle asdescribed above in the general area of a nerve bundle, positioning theechogenic needle adjacent the nerve bundle utilizing sonic imagingtechniques, introducing an echogenic catheter configured for controlleddelivery of a fluid as described above through the echogenic needle,withdrawing the echogenic needle, positioning the echogenic catheteradjacent the nerve bundle utilizing sonic imaging techniques, anddelivering fluid to the nerve bundle through the echogenic catheter.

The above-described system for performing a new block procedure mayfurther include the steps of placing a sheath over the echogenic needleprior to introducing the echogenic needle adjacent the general area ofthe nerve bundle and withdrawing the echogenic needle while maintainingthe sheath in place and then advancing the echogenic catheter throughthe sheath. The sheath may be an echogenic as generally described above.

The present invention also encompasses another apparatus for performinga nerve block procedure. This apparatus includes an echogenic softtissue tunneling device for creating a subcutaneous path for placementof a catheter in a patient and an echogenic catheter configured forcontrolled delivery of a medication.

Exemplary soft tissue tunneling devices are described at, for example,U.S. Patent Application Publication No. US 2008/0086161 A1 for “SoftTissue Tunneling Device” published Apr. 10, 2008 by Massengale et al.;and U.S. Patent Application Publication No. US 2008/0312677 A1 for “SoftTissue Tunneling Device” published Dec. 18, 2008 by Massengale et al.;the entire contents of each is incorporated herein by reference.

For example, these soft tissue tunneling devices include an elongateshaft having a rounded distal end. The distal end and/or the elongateshaft may be made echogenic in a manner similar to the echogenic needleand/or catheter as described above. These devices may further include ahandle secured to the shaft in which the handle is configured to permita user of the tunneling device to manually manipulate the tunnelingdevice. The elongate shaft may be malleable so as to permit a shape ofthe shaft to be altered prior to use of the tunneling device. Forexample, the shaft may have a non-linear shape including, but notlimited to, a curved shape.

The apparatus further includes a sheath positionable over a portion ofthe shaft. The sheath has a snug fit with the shaft such that the sheathand the shaft can be advanced together and positioned within a body of apatient. According to the invention, at least one of the elongate shaftand sheath are echogenic. That is, the elongate shaft of the tissuetunneling device may be echogenic, the sheath may be echogenic, or bothmay be echogenic.

According to an aspect of the apparatus for performing a nerve blockprocedure, the elongate shaft of the echogenic soft tissue tunnelingdevice may define an interior lumen. In addition, the tunneling devicemay include at least one fluid exit opening positioned along the lengthof the shaft and extending from the interior lumen to an externalsurface of the shaft, and an inlet to the interior lumen to permitliquid to be introduced into the interior lumen and administered to thepatient through the at least one fluid exit opening. The apparatus mayfurther include a sheath slidably positioned on the elongate shaft suchthat at least one of the elongate shaft and sheath is echogenic

In another aspect of the invention, the tunneling device may furtherinclude a retractable needle located at the distal end of the elongateshaft. The retractable needle can be used to assist in puncturing theskin prior to advancing the tunneling device within the patient's body.The retractable needle can be housed within the distal end of a needlelumen, and may be fully retracted within the needle lumen so that theelongate shaft maintains a substantially blunt distal end. The positionof the retractable needle within the needle lumen may be changed usingany suitable method.

The present invention also encompasses a system for performing a nerveblock procedure utilizing the echogenic soft tissue tunneling devicedescribed above. Generally speaking, the system includes the steps of:(i) grasping the handle of an echogenic soft tissue tunneling device forcreating a subcutaneous path for placement of a catheter in a patient—inwhich the tunneling device includes an elongate shaft having a roundeddistal end and defining at least one interior lumen and at least onefluid exit opening in fluid communication with the interior lumen; (ii)introducing the echogenic tunneling device into the body of a patient inthe general area of a nerve bundle; (iii) positioning the echogenictunneling device adjacent the nerve bundle utilizing sonic imagingtechniques; (iv) withdrawing the echogenic tunneling device; (v)introducing an echogenic catheter configured for controlled delivery ofa fluid through the subcutaneous path created by the echogenic tunnelingdevice; (vi) positioning the echogenic catheter adjacent the nervebundle utilizing sonic imaging techniques, and (vii) delivering fluid tothe nerve bundle through the echogenic catheter.

In an aspect of the system, the echogenic tunneling device may furtherinclude a sheath that slidably surrounds a portion of the shaft, suchthat the system further includes the steps of (a) introducing andadvancing the sheath along with the introducing and positioning of thetunneling device, and (b) withdrawing the shaft from the sheath andleaving the sheath within the body. When such a sheath is utilized inthe system, at least one of the tunneling device and the sheath shouldbe echogenic.

While various patents have been incorporated herein by reference, to theextent there is any inconsistency between incorporated material and thatof the written specification, the written specification shall control.In addition, while the disclosure has been described in detail withrespect to specific embodiments thereof, it will be apparent to thoseskilled in the art that various alterations, modifications and otherchanges may be made to the disclosure without departing from the spiritand scope of the present disclosure. It is therefore intended that theclaims cover all such modifications, alterations and other changesencompassed by the appended claims.

What is claimed is:
 1. An apparatus for performing a nerve blockprocedure, the apparatus comprising an echogenic needle and an echogeniccatheter insertable through the echogenic needle and configured forcontrolled delivery of a medication, the echogenic catheter comprisingan elongated tubular member having walls and an echogenic catheter tip,the echogenic catheter tip comprising one of: an echogenic insertentirely within the tubular member or; an echogenic plug including asupport that resides within the tubular member, the echogenic insert andechogenic plug having a shape that reflects an effective amount ofacoustic waves so the catheter tip is satisfactorily visible duringsonic imaging, the shape being selected from gear shapes, hourglassshapes, hemisphere-terminated cylinder shapes, and multi-facetedgeometric shapes formed by interlocking polygons, the echogenic insertand the echogenic plug having edges that engage the walls of the tubularmember to prevent the echogenic insert and echogenic plug from movingrelative to the elongated tubular member, wherein the edges and thewalls of the tubular member, when engaged, define a plurality of groovesor notches between the edges and the walls of the tubular member.
 2. Theapparatus of claim 1, wherein the echogenic needle has a distal endcomposed of an echogenic needle tip, a hollow needle body, and aproximal end that includes a fitting.
 3. The apparatus of claim 2,wherein the needle body is an echogenic needle body.
 4. The apparatus ofclaim 3, wherein at least a portion of the needle tip and/or needle bodyincorporates or is coated with a material that increases acousticimpedance.
 5. The apparatus of claim 4, wherein the material is from thegroup consisting of titanium carbide, titanium nitride, titaniumaluminum nitride, and titanium aluminum carbon nitride.
 6. The apparatusof claim 4, wherein the material is a hard, dense, amorphousnon-crystalline solid.
 7. The apparatus of claim 6, wherein the materialis selected from glass, poly(methyl methacrylate), and hard, glassyhydrogels.
 8. The apparatus of claim 1, wherein the echogenic cathetertip is formed from or coated with cobalt chrome, glass, or othermaterial having a high degree of acoustic impedance.
 9. The apparatus ofclaim 1, further comprising an echogenic sheath.
 10. An echogeniccatheter configured for controlled delivery of a fluid across ananatomical region, the echogenic catheter comprising: an elongatedtubular member having walls, and an echogenic catheter tip comprisingone of an echogenic insert entirely within the tubular member or; anechogenic plug including a support that resides within the tubularmember, the echogenic plug and echogenic insert having a shape thatreflects an effective amount of acoustic waves so the tip issatisfactorily visible during sonic imaging, the shape being selectedfrom gear shapes, hourglass shapes, hemisphere-terminated cylindershapes, and multi-faceted geometric shapes formed by interlockingpolygons, the echogenic insert and the echogenic plug having edges thatengage the walls of the tubular member to prevent the echogenic insertand echogenic plug from moving relative to the elongated tubular member,wherein the edges and the walls of the tubular member, when engaged,define a plurality of grooves or notches between the edges and the wallsof the tubular member.
 11. The echogenic catheter of claim 10, whereinthe echogenic catheter tip is formed from or coated with cobalt chrome,glass, or other material having a high degree of acoustic impedance.